For some circulating devices such as fans, pumps, rotary vanes, and compressors, guide members or housing shapes may be used to direct flow of the air or circulating medium to or from the rotors. However, the shape, configuration, and/or orientation of these guide members typically would be designed for flow considerations in one direction only, for example.
Additional difficulties with existing systems may be appreciated in view of the Detailed Description of Example Embodiments, below.